Peter Vestinos is Iron Chef Liquor. In October, Vestinos, head barkeep at Sepia (123 North Jefferson), beat out a host of local luminaries, including Adam Seger of Nacional 27, in an Iron Bar Chef competition.

Curious about the guy who bested some of Chicago’s top mixologists, I stopped in at Sepia last Monday night. The restaurant was behind on its second turn and folks stood three-deep behind the bar. People threw money, waitresses angled for orders and gray-hairs in Brooks Brother’s button-downs demanded infinite configurations of vodka. I was horrified. And not because I was getting boxed out by a gaggle of “Sex in the City” wannabe’s sipping sherry, but by the volume of vodka requests.

Vestinos offered up a terrific cocktail program based on house-made sour mix, grenadine, infused liquors and bitters, but all they wanted was to pay $14 bucks for a clear, colorless, odorless, tasteless liquid. Using this logic, you’d expect them to ignore the restaurant menu and demand chicken nuggets from Sepia’s chef Kendal Duque.

While my inner tastemaker wanted to kick ass, Vestinos forded the maelstrom, rifling through wineglasses, pumping his gleaming tin shaker, all the while deploying a severe poker face. And, unlike at the Violet Hour where it takes a day to make one drink, Vestinos kicked out the occasional craft cocktail in minutes. After witnessing this, I’d also dub him Iron Chef Stoic.

He’s not immune to what’s going on, saying, “You just gotta pick your battles.” He adds, “I’ve had people look at my cocktail list, hand it back and say, ‘I want to see your martini list. These aren’t cocktails.’ It’s not their fault. People have forgotten how to drink, just like they forgot how to eat or to drink wine.”

Part of the reason Vestinos might be so good at maintaining a visual cool is that he’s a sketch-comedy actor and writer. He founded the local troupe 37Foxtrot, and wrote and performed a one-man show, “Cooking Light with Ms. Berndadette,” based on fake Discovery Center classes gone awry, last year.

Bartending was a role he never would have predicted. As the only member of his family to go to college, and the son of a career bartender, he swore he’d never keep bar. After years of producing corporate videos, he enrolled in bartending school and landed a job at Cyrano’s Bistro. He says, “I made more in two days than in two weeks with the other job.”

He moved on to the Tasting Room, and while on a trip to New York, he ran into a whiskey smash at Audrey Sander’s Pegu Club. Vestinos says, “There was this Gourmet article on Audrey talking about not having vodka on the back shelf and no soda guns at the bar. I was like, that’s crazy. The whiskey smash I ordered was like discovering wine. There was this bouquet, and the whiskey was bright and light. I came back the next night. ”

Back in Chicago he pored through classic tomes like the Mr. Boston guides and works by Dale DeGroff. As an innovator, he started building his drinks in the glass side of his Boston shaker, as opposed to the tin side where most bartenders work. He says, “I want customers to see what’s going on.”

When he organized the bar at Sepia, Vestinos featured gins on the center shelf and flanked them with whiskeys, cordials and rums, and de-emphasized vodka by putting it on the bottom shelf.

He keeps a bouquet of fresh aromatics like mint in ice water on the back bar and juices his limes with a citrus squeezer bar side. He says, “People order a Cosmo and they’ve never seen anyone make it with a fresh lime. The smell that floats across the bar is amazing.”

Vestinos has also become a cultural scientist. He says when people order vodka cocktails, they are very specific about the garnish because it’s the only thing they can control. He says, “You have people asking for one regular olive and one blue cheese olive, or one olive and a twist.” Sensing a customer’s desire for creativity, he might suggest they try gin, as “it’s the original flavored vodka.”

If those folks bite, they’ll find a fizzy French 75, Hendricks Gin hit with a demi-sec rosé float where the aroma off the glass drops like a grapefruit and lemon bomb. Vestino’s old-fashioned made with fig- and almond-infused Woodford Reserve bourbon and homemade cranberry bitters reinvigorates the syrupy drink we’ve come to associate with brandy-soaked Wisconsinites, as a balanced clean sipper. His dark n’ stormy is like a gingerbread cookie soaked in rum and features a floating storm cloud of ruby port. Even his fruitier fare, such as the Pear Nectar (gin with agave nectar, lemon and egg white), is balanced with the slight bitterness of a pear-green-tea–infused Plymouth Gin.

While Vestinos is focused on his craft, you might want to get to Sepia soon just in case Hollywood comes calling. As Vestino’s says, “The other day, my girlfriend said, this mixology thing seems to be working out. I told her, well, the acting thing is going pretty well, too.”